1. Field of the Invention
This invention relates generally to an improved catheter placement system and, more specifically, to an improved catheter structure.
2. Description of the Prior Art
Catheters are useful for administering fluids into the body, performing blood transfusions, removal of body fluid, blood pressure determinations, and the like.
A conventional catheter device may be put in place by any of several well known methods. In one method, the skin is cut surgically and the tip of the catheter is inserted directly into the body.
Alternatively, a needle (or cannula) is inserted into the skin and the catheter is passed through the needle to insert the catheter into the body. If the needle is left in the original position after the catheter has been inserted into the body, the catheter may be cut by the needle or there may be a risk of the needle damaging the patient's body. Therefore, the needle is usually withdrawn, leaving the catheter inserted. In order to be able to remove the needle from the external end of the catheter, a fixture having a larger size than that of the catheter must not be connected to the external end of the catheter until the needle has been removed. The needle must be removed manually, and a fitting must be subsequently installed at the external end of the catheter. Afterward, the desired instrument can be connected to the fitting.
Recently, prepackaged products which are sterilized in advance have been in demand in an effort to minimize the amount of contact with the physician. This is to minimize the contamination during the placement procedure. From this standpoint, the above-mentioned conventional methods for the insertion of catheters are not satisfactory.
In one product which has been marketed in recent years, the entire catheter device including an external fitting is sterilized and sealed in a package. When the catheter apparatus is needed, the package is opened at the end where the insertion tip of the catheter is located, and the tip is inserted into the body. The catheter is gradually inserted through a cannula directly from the package.
The cannula is always kept in its original insertion position. Thus, this apparatus has the drawback that such a cannula cannot be used in certain parts of the body. For example, the above-mentioned apparatus is not suited for insertion from the neck to the subclavian vein.